I have seen devices from $40 to $300. How do they work? Would they shut off power to entire home? Need to be replaced after significant surge?

02-25-2014, 11:48 AM

The Semi-Retired Electric

Re: whole house surge suppressors

SPD's or Surge Protective Devices have replaced "Surge Suppressors".

They are now called SPD "Version 3" and are designed to be connected : 1) directly across the incoming power line 2) across a 2 Pole breaker 3) plugged into a receptacle, at the appliance. these are/were called "surge strips".

They usually contain MOV's (metal oxide varistors) set to block any spikes or surges above a certain level.
If the surge is very great they will trip the breaker or destroy themselves, instead of sensitive equipment.

The higher the joule number the better.

A #2 (above) and several #3 (above) strips in each home are good investments.

02-25-2014, 10:04 PM

jmsdallas

Re: whole house surge suppressors

I had 3 CyberPower 575SL ups devices connected to electronic devices in my home. Recently a particular bad electronic surge ruined each of these ups devices. The devices would no longer charge the ups batteries. None of the electronic devices attached to the ups's were damaged. I also lost a space heater, several clocks, and a home intercom system. A surge strip also was effected so as to leave a carbon like deposit on the carpet where it was protecting a TV. So now I am thinking that I want to add a surge device at the breaker box. Looking at a Leviton 51120, a GE THSASURGE60, and a SUPCO SCM150. All are similar bus somewhat different specs. The GE unit claims a 1 nanosec response time and claims protection for electronics. The SUPCO unit a <5 nanosec response and dis-claims electronic protection. Any thoughts on these devices. They all attach in identical manner to the breaker box.

02-25-2014, 10:39 PM

The Semi-Retired Electric

Re: whole house surge suppressors

I'm not familiar with the models you list but believe there is not much difference with any of them.

At least three MOV's are required for 120V protection, I will usually install them in equipment I design, since they cost less than $1 each. I never had any lightning damaged equipment.

Industrial SPD's (costing several hundred dollars) first showed up in riveted cases, with labels that said "warranty void if opened. Of course, I opened mine immediately and found they had soldered about 20 together to create 3 huge bundles.

There have been recent cases where Surge Strips burned the surface (carpet) they were sitting on, so it's best to set them on something non-flammable.

02-26-2014, 11:49 AM

jmsdallas

Re: whole house surge suppressors

I cannot tell if the damaged ups's were still protecting against surges? Power was still being supplied through the "surge protected" receptacles. The failure mode was that the backup batteries were not being charged even with new batteries. Is there a method to test if a device is still protecting against surges?

The surge-only devices that stained the carpet did so through the two holes on the bottom that serve to attach the device via flat head screws. It didn't burn, just deposited a black carbon like substance on the carpet. It came off with a cleaning fluid. Still good advise not to lay a surge protector on carpet.

The surprising thing to me was that the ups's were not able to protect their own battery switching circuits from the surge and subsequently failed even though they apparently protected my downstream devices.

In addition to the CyberPower units I had two APC ups's that did not fail.

02-26-2014, 01:45 PM

daspyda

Re: whole house surge suppressors

Many power companies are making these available for a nominal monthly charge.

02-26-2014, 06:31 PM

HoustonRemodeler

Re: whole house surge suppressors

All you need is to be near the lightning.

A few years back I was at my desk in the center of my home when a storm rolled through. A bolt of lightning struck the street in front of the house, about 60 feet from where I was sitting. Made a cup sized hole in the asphalt.

I felt the EM field pass through the house and my body.

The GFI in the front bathroom tripped - no damage.

The front bedroom circuit breaker tripped - no damage

The GFI in the half bath tripped - no damage

As the EM wave progressed through the house it fried the cable TV box, and my motherboard, even though both were plugged into newer power surge strips. Luckily my hard drive was OK

02-26-2014, 06:35 PM

The Semi-Retired Electric

Re: whole house surge suppressors

[QUOTE=jmsdallas;287405]I cannot tell if the damaged ups's were still protecting against surges? Power was still being supplied through the "surge protected" receptacles. The failure mode was that the backup batteries were not being charged even with new batteries. Is there a method to test if a device is still protecting against surges?

The surge-only devices that stained the carpet did so through the two holes on the bottom that serve to attach the device via flat head screws. It didn't burn, just deposited a black carbon like substance on the carpet. It came off with a cleaning fluid. Still good advise not to lay a surge protector on carpet.

The surprising thing to me was that the ups's were not able to protect their own battery switching circuits from the surge and subsequently failed even though they apparently protected my downstream devices.

In addition to the CyberPower units I had two APC ups's that did not fail.[/QUOTE]

The easiest way to tell if a ups is working is to unplug the ups and see how long it will power the load. 15 min. is typical for a fair system.

A surge strip will sometimes power a load but be completely destroyed. Some have lights to indicate if they are still providing protection. They're so inexpensive that if one shows any sign of damage I would replace it.

Some carry a warranty and insurance if equipment downstream is damage but I've never heard of anyone cashing in on that feature.

Lightning can be so destructive I would consider myself very blessed if my house was subject to a strike and my family and I made it out alive.

03-08-2014, 11:04 AM

Mastercarpentry

Re: whole house surge suppressors

Replace surge strips regularly- the MOV's deteriorate each time they go to work so the protection level gets lower each time they clamp a surge. Every 3-5 years is usually good, but if you know they have been put to the test (other unprotected equipment damage) replace them ASAP. They're cheap insurance but the cheapest models are hardly worth their cost. Get ones made for computer servers if you want best protection. Also these don't work as advertised when plugged into another surge strip; the downstream one may not activate due to reduced current from the upstream on but still allow enough to flow through to damage sensitive electronics. I'd imagine whole-house systems use better higher-rated MOV's to compensate for wear-and-tear but always check with the manufacturer.

If you can prove that a lightening-induced surge occurred through the utility lines, you may be able to recover your loss expenses from them. Your regular homeowners policy may not meet the deductible for surge damage, but many policies will offer an upgrade or rider to cover this completely now that most electrical stuff is also electronic in nature. Those few extra bucks on the premium are well worth it- check with your agent.